Sevoflurane Concentration (sevoflurane + concentration)

Distribution by Scientific Domains

Kinds of Sevoflurane Concentration

  • end-tidal sevoflurane concentration


  • Selected Abstracts


    Comparison of breathing tube connectors during invasive bronchial procedures,

    ANAESTHESIA, Issue 6 2009
    N. Rahe-Meyer
    Summary Bronchoscopy and bronchial suctioning during intra-operative artificial ventilation often causes leakage from the ventilation circuit with a decrease in ventilatory parameters and possible workplace contamination with anaesthetic gases. Different connectors have been developed to reduce gas leakage. We evaluated the following connectors : VBM 2 mm, 3 mm and 5 mm, Bodai Suction-Safe, Bodai Bronch-Safe and Bodai Trach-Safe, as well as the BE 105-7, BE 105-8 and SH 7-45. Invasive bronchial instruments (catheters, bronchoscopes and bronchial blockers) with 1.67,7.33 mm diameter were used. Pressure-controlled ventilation was performed on a test lung using a ventilator. Sevoflurane concentration in the room was measured 0.2 and 1.5 m from the connector using a photo-acoustic infrared-spectroscope. The VBM connectors caused the least gas leak and ensured stability of ventilation parameters even at peak pressures when combined with smaller instruments. With instruments > 6 mm, BE 105-7, BE 105-8 and SH 7-45 connectors performed best. The Bodai connectors showed a reduced ability to prevent leakage and to keep ventilatory parameters stable. All connectors, excluding the Bodai Trach-Safe, prevented exposure to anaesthetic gases beyond the current safety recommendations when combined with the fitting instruments. The connectors showed different ranges of tightness, equivalent to different ranges of compatibility with the instruments used. [source]


    Experience with remifentanil,sevoflurane balanced anesthesia for abdominal surgery in neonates and children less than 2 years

    PEDIATRIC ANESTHESIA, Issue 6 2008
    FABRICE MICHEL MD
    Summary Background:, Few data report remifentanil use in the neonatal population. We described here our experience with remifentanil,sevoflurane balanced anesthesia in neonates and children less than 2 years who underwent general anesthesia for abdominal surgery. Methods:, We retrospectively studied the pattern of remifentanil infusion associated with sevoflurane inhalation in preterm neonates (PTN; n = 18) (born before 37 weeks of gestation and <45 weeks of postmenstrual age), full-term neonates (FTN; n = 21) (born after 37 weeks of gestation and less than 29 days old) and older children up to 2 years (CUT; n = 24). We recorded heart rate (HR), mean arterial pressure (MAP), mean remifentanil dose and sevoflurane concentration before incision and at 5, 10, 20, 30, 45, 60, 90, and 105 min after incision. Results:, We observed that remifentanil doses used during surgery were lower in PTN than in both FTN and CUT and lower in FTN than in CUT. This was because of a progressive decrease in remifentanil dose during anesthesia in PTN and FTN. Conversely, remifentanil doses increased in CUT during anesthesia. Sevoflurane concentrations were higher in CUT group than in PTN and FTN groups. MAP and HR did not vary in the three groups during anesthesia. Conclusions:, Remifentanil,sevoflurane anesthesia can be used for general anesthesia in neonates. We observed that anesthetists used lower doses of remifantanil and lower concentrations of sevoflurane in neonates compared with the older children. [source]


    Personnel breathing zone sevoflurane concentration adherence to occupational exposure limits in conjunction with filling of vaporisers

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 9 2010
    H. HEIJBEL
    Background: Work place pollution during filling of anaesthetic vaporisers has been a matter of concern. We studied personnel breathing zone ambient air sevoflurane concentrations during filling of sevoflurane with three different filling systems: Quik-FilÔ for Abbott and Dräger FillÔ resp. Easy-FilÔ adapters for Baxter sevoflurane bottles, referred to as ,Abbott and Baxter filling systems'. Method: Sequential filling of three vaporisers was performed for a 15-min period, once with each of Abbott and Baxter filling systems, by four nurses. Ambient-air sevoflurane p.p.m. concentration in the breathing zone was continuously measured using a Miran 1a device during filling, and the mean 15 min sevoflurane concentration was calculated. Results: All eight measured (4 × 2 sequences) 15-min mean breathing zone sevoflurane concentrations covering filling of three vaporisers were well below the recommended short-term value (STV) provided by the Swedish Work Environment Authority (STV 20 p.p.m.). Conclusion: The breathing zone sevoflurane concentration during filling of sevoflurane with Baxter or Abbott filling systems, in an ordinary operating theatre, was found to be reassuringly below the Swedish recommended STV (20 p.p.m. average for a 15-min period). [source]


    Spectral entropy monitoring allowed lower sevoflurane concentration and faster recovery in children

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 7 2010
    S. R. CHOI
    Background: Anesthetic titration using spectral entropy monitoring reduces anesthetic requirements and shortens recovery in adult surgical patients. This study was performed to evaluate the effect of entropy monitoring on end-tidal sevoflurane concentration and recovery characteristics in pediatric patients undergoing sevoflurane anesthesia. Methods: Seventy-eight children (aged 3,12 years) scheduled for a tonsillectomy and/or an adenoidectomy were randomly divided into one of two groups: standard practice (Standard) or entropy-guided (Entropy). In the Standard group, sevoflurane was adjusted to maintain the heart rate and systolic blood pressure (BP) within 20% of the baseline values. In the Entropy group, sevoflurane was adjusted to achieve a state entropy of 40,50. We compared the entropy values, end-tidal sevoflurane concentration and recovery times between groups. Results: During maintenance of anesthesia, the entropy and BP values were higher in the Entropy group (P<0.05). The end-tidal sevoflurane concentration during maintenance was lower in the Entropy group (2.2 (0.3) vol%) compared with the Standard group (2.6 (0.4) vol%) (P<0.05). Recovery times were faster in the Entropy group (P<0.05). Conclusions: Compared with standard practice, we found that entropy-guided anesthetic administration was associated with a reduced sevoflurane concentration and a slightly faster emergence and recovery in 3,12-year-old children. [source]


    Lidocaine vs. magnesium: effect on analgesia after a laparoscopic cholecystectomy

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 5 2010
    I. M. SAADAWY
    Background: This double-blinded study aimed at evaluating and comparing the effects of magnesium and lidocaine on pain, analgesic requirements, bowel function, and quality of sleep in patients undergoing a laparoscopic cholecystectomy (LC). Methods: Patients were randomized into three groups (n=40 each). Group M received magnesium sulfate 50 mg/kg intravenously (i.v.), followed by 25 mg/kg/h i.v., group L received lidocaine 2 mg/kg i.v., followed by 2 mg/kg/h i.v., and group P received saline i.v. Bolus doses were given over 15 min before induction of anesthesia, followed by an i.v. infusion through the end of surgery. Intraoperative fentanyl consumption and averaged end-tidal sevoflurane concentration were recorded. Abdominal and shoulder pain were evaluated up to 24 h using a visual analog scale (VAS). Morphine consumption was recorded at 2 and 24 h, together with quality of sleep and time of first flatus. Results: Lidocaine or magnesium reduced anesthetic requirements (P<0.01), pain scores (P<0.05), and morphine consumption (P<0.001) relative to the control group. Lidocaine resulted in lower morphine consumption at 2 h [4.9 ± 2.3 vs. 6.8 ± 2.8 (P<0.05)] and lower abdominal VAS scores compared with magnesium (1.8 ± 0.8 vs. 3.2 ± 0.9, 2.2 ± 1 vs. 3.6 ± 1.6, and 2.1 ± 1.4 vs. 3.3 ± 1.9) at 2, 6, and 12 h, respectively (P<0.05). Lidocaine was associated with earlier return of bowel function and magnesium was associated with better sleep quality (P<0.05). Conclusion: I.v. lidocaine and magnesium improved post-operative analgesia and reduced intraoperative and post-operative opioid requirements in patients undergoing LC. The improvement of quality of recovery might facilitate rapid hospital discharge. [source]


    Experience with remifentanil,sevoflurane balanced anesthesia for abdominal surgery in neonates and children less than 2 years

    PEDIATRIC ANESTHESIA, Issue 6 2008
    FABRICE MICHEL MD
    Summary Background:, Few data report remifentanil use in the neonatal population. We described here our experience with remifentanil,sevoflurane balanced anesthesia in neonates and children less than 2 years who underwent general anesthesia for abdominal surgery. Methods:, We retrospectively studied the pattern of remifentanil infusion associated with sevoflurane inhalation in preterm neonates (PTN; n = 18) (born before 37 weeks of gestation and <45 weeks of postmenstrual age), full-term neonates (FTN; n = 21) (born after 37 weeks of gestation and less than 29 days old) and older children up to 2 years (CUT; n = 24). We recorded heart rate (HR), mean arterial pressure (MAP), mean remifentanil dose and sevoflurane concentration before incision and at 5, 10, 20, 30, 45, 60, 90, and 105 min after incision. Results:, We observed that remifentanil doses used during surgery were lower in PTN than in both FTN and CUT and lower in FTN than in CUT. This was because of a progressive decrease in remifentanil dose during anesthesia in PTN and FTN. Conversely, remifentanil doses increased in CUT during anesthesia. Sevoflurane concentrations were higher in CUT group than in PTN and FTN groups. MAP and HR did not vary in the three groups during anesthesia. Conclusions:, Remifentanil,sevoflurane anesthesia can be used for general anesthesia in neonates. We observed that anesthetists used lower doses of remifantanil and lower concentrations of sevoflurane in neonates compared with the older children. [source]


    The reliability of endtidal CO2 in spontaneously breathing children during anaesthesia with Laryngeal Mask AirwayTM, low flow, sevoflurane and caudal epidural

    PEDIATRIC ANESTHESIA, Issue 5 2002
    Per AASHEIM MD
    Background: Noninvasive devices for monitoring endtidal CO2 (PECO2) are in common use in paediatric anaesthesia. Questions have been raised concerning the reliability of these devices in spontaneous breathing children during surgery. Our anaesthetic technique for elective infraumbilical surgery consists of spontaneous breathing through a Laryngeal Mask Airway (LMATM), low fresh gas flow, sevoflurane and a caudal epidural. We wanted to compare PECO2 and arterial CO2 (PaCO2) during surgery. Methods: Twenty children, aged 1,6 years, scheduled for infraumbilical surgery, were studied and one arterial sample was taken 45 min after induction of anaesthesia. PECO2, inspiratory PCO2, oxygen saturation, heart rate, respiratory rate, mean arterial blood pressure and expiratory sevoflurane concentration were measured every 5 min. The respiratory and circulatory parameters were stable during surgery. Results: The mean PaCO2 , PECO2 difference was 0.15 (0.16) kPa [1.1 (1.2 mmHg)]. Conclusions: PECO2 is a good indicator of PaCO2 in our anaesthetic setting. [source]


    Effects of different doses of remifentanil on the end-tidal concentration of sevoflurane required for tracheal intubation in children

    ANAESTHESIA, Issue 8 2009
    L. He
    Summary We investigated the effects of different doses of remifentanil on the end-tidal concentration of sevoflurane required for tracheal intubation in children without the use of neuromuscular blocking drugs. One hundred and thirty paediatric patients, aged 3,8 years, were randomly allocated to receive no remifentanil (group control) or remifentanil 0.1 ,g.kg,1.min,1 (group remi0.1), 0.2 ,g.kg,1.min,1 (group remi0.2), 0.3 ,g.kg,1.min,1 (group remi0.3). All patients were anaesthetised using 5% sevoflurane. After loss of eyelash reflex, remifentanil 1 ,g.kg,1 was injected over 1 min followed by an appropriate group-dependent infusion and the end-tidal sevoflurane concentration was changed. Predetermined end-tidal sevoflurane concentrations for each group were determined using the Dixon up-and-down method. After the target concentration of sevoflurane was maintained for 5 min, the child's trachea was intubated. Successful intubation was defined as excellent or good intubating conditions. The end-tidal concentration (SD) of sevoflurane for successful tracheal intubation in 50% of children (ED50) were 5.16 (0.22)% in control, 3.27 (0.18)%, 1.81 (0.20)% and 1.01 (0.11)%, in remi0.1, remi0.2, and remi0.3 groups, respectively. Using probit analysis, the 95% effective dose (ED95) of sevoflurane were 5.60% (95% CI 5.35,7.66), 3.77% (95% CI 3.45,7.74), 2.18% (95% CI 1.96,3.86), 1.19% (95% CI 1.06,1.82) in control, remi0.1, remi0.2, and remi0.3 groups, respectively. [source]


    Spike-monitoring of anaesthesia for corpus callosotomy using bilateral bispectral index

    ANAESTHESIA, Issue 7 2009
    S. Ogawa
    Summary During corpus callosotomy for intractable epilepsy, the electrocorticogram is commonly recorded from electrodes placed on the brain surface to monitor of epileptic activity and assess the synchronisation of epileptic signals between the left and the right hemispheres. We evaluated the usefulness of bilateral bispectral index monitoring using two monitors and two sensors placed above the frontal region. Spikes were readily detected on the electroencephalogram on the bispectral index monitor, and the frequency of their occurrence increased or decreased in response to adjustment of the sevoflurane concentration. The disappearance of synchronisation between the left and the right hemispheres was observed with use of the bispectral index , in concordance with the electrocorticogram. Thus, ,spike-monitoring anaesthesia' using bilateral bispectral index was useful in assessing both the effect of anaesthetics on the electroencephalogram signals and the surgical therapeutic effect. [source]


    Monitoring pollution by proton-transfer-reaction mass spectrometry during paediatric anaesthesia with positive pressure ventilation via the laryngeal mask airway or uncuffed tracheal tube

    ANAESTHESIA, Issue 7 2002
    J. Rieder
    Summary Twenty children aged 2,66 months were randomly allocated for airway management with either the laryngeal mask airway or uncuffed tracheal tube using intermittent positive pressure ventilation with a tidal volume of 8 ml.kg,1 and a respiratory rate adjusted to maintain end-expiratory carbon dioxide concentration at 5.3 kPa. Induction was with fentanyl/propofol and maintenance was with sevoflurane 2.5% in oxygen/air. The airway device was removed when the patients were awake and the patients were transferred to the postanaesthesia care unit 10 min later. Air was sampled from a point 1.5 m above the floor at a location remote from the ventilation outlet and analysed using a proton-transfer-reaction mass spectrometer capable of continuous trace gas analysis at the parts per billion volume (ppbv) level. The concentration of sevoflurane was recorded every minute during three consecutive phases: for 5 min before the introduction of sevoflurane (background); after introduction of sevoflurane until removal of the airway device (intra-operative); and every minute after removal until the concentration returned to background levels. Median (interquartile range [range]) intra-operative sevoflurane concentrations were 200,400 times higher than background values for the laryngeal mask airway 1 (1,2 [0,3]) ppbv vs. 404 (278,523 [83,983]) ppbv, respectively, and the tracheal tube 2 (1,3 [0,5]) ppbv vs. 396 (204,589 [107,1735]) ppbv (both p <,0.0001), and returned to background values within 5 min of removal. There were no differences in sevoflurane concentration between devices intra-operatively or after removal. The performance of the proton-transfer-reaction mass spectrometer was identical at the start and end of the 30-day study. We conclude that peri-operative sevoflurane concentration in a modern operating theatre is similar for the laryngeal mask airway and the uncuffed tracheal tube in paediatric patients receiving intermittent positive pressure ventilation. Intra-operative sevoflurane concentrations are five times lower than occupational safety limit requirements, and 1000 times lower 5 min after removal of the airway device with the patient awake. The proton-transfer-reaction mass spectrometer has potential for monitoring air quality in the operating theatre. [source]


    Personnel breathing zone sevoflurane concentration adherence to occupational exposure limits in conjunction with filling of vaporisers

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 9 2010
    H. HEIJBEL
    Background: Work place pollution during filling of anaesthetic vaporisers has been a matter of concern. We studied personnel breathing zone ambient air sevoflurane concentrations during filling of sevoflurane with three different filling systems: Quik-FilÔ for Abbott and Dräger FillÔ resp. Easy-FilÔ adapters for Baxter sevoflurane bottles, referred to as ,Abbott and Baxter filling systems'. Method: Sequential filling of three vaporisers was performed for a 15-min period, once with each of Abbott and Baxter filling systems, by four nurses. Ambient-air sevoflurane p.p.m. concentration in the breathing zone was continuously measured using a Miran 1a device during filling, and the mean 15 min sevoflurane concentration was calculated. Results: All eight measured (4 × 2 sequences) 15-min mean breathing zone sevoflurane concentrations covering filling of three vaporisers were well below the recommended short-term value (STV) provided by the Swedish Work Environment Authority (STV 20 p.p.m.). Conclusion: The breathing zone sevoflurane concentration during filling of sevoflurane with Baxter or Abbott filling systems, in an ordinary operating theatre, was found to be reassuringly below the Swedish recommended STV (20 p.p.m. average for a 15-min period). [source]


    Effects of subanaesthetic and anaesthetic doses of sevoflurane on regional cerebral blood flow in healthy volunteers.

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 10 2004
    A positron emission tomographic study
    Background:, We tested the hypothesis that escalating drug concentrations of sevoflurane are associated with a significant decline of cerebral blood flow in regions subserving conscious brain activity, including specifically the thalamus. Methods:, Nine healthy human volunteers received three escalating doses using 0.4%, 0.7% and 2.0% end-tidal sevoflurane inhalation. During baseline and each of the three levels of anaesthesia one PET scan was performed after injection of . Cardiovascular and respiratory parameters were monitored and electroencephalography and bispectral index (BIS) were registered. Results:, Sevoflurane decreased the BIS values dose-dependently. No significant change in global cerebral blood flow (CBF) was observed. Increased regional CBF (rCBF) in the anterior cingulate (17,21%) and decreased rCBF in the cerebellum (18,35%) were identified at all three levels of sedation compared to baseline. Comparison between adjacent levels sevoflurane initially (0 vs. 0.2 MAC) decreased rCBF significantly in the inferior temporal cortex and the lingual gyrus. At the next level (0.2 MAC vs. 0.4 MAC) rCBF was increased in the middle temporal cortex and in the lingual gyrus, and decreased in the thalamus. At the last level (0.4 MAC vs. 1 MAC) the rCBF was increased in the insula and decreased in the posterior cingulate, the lingual gyrus, precuneus and in the frontal cortex. Conclusion:, At sevoflurane concentrations at 0.7% and 2.0% a significant decrease in relative rCBF was detected in the thalamus. Interestingly, some of the most profound changes in rCBF were observed in structures related to pain processing (anterior cingulate and insula). [source]


    Effects of different doses of remifentanil on the end-tidal concentration of sevoflurane required for tracheal intubation in children

    ANAESTHESIA, Issue 8 2009
    L. He
    Summary We investigated the effects of different doses of remifentanil on the end-tidal concentration of sevoflurane required for tracheal intubation in children without the use of neuromuscular blocking drugs. One hundred and thirty paediatric patients, aged 3,8 years, were randomly allocated to receive no remifentanil (group control) or remifentanil 0.1 ,g.kg,1.min,1 (group remi0.1), 0.2 ,g.kg,1.min,1 (group remi0.2), 0.3 ,g.kg,1.min,1 (group remi0.3). All patients were anaesthetised using 5% sevoflurane. After loss of eyelash reflex, remifentanil 1 ,g.kg,1 was injected over 1 min followed by an appropriate group-dependent infusion and the end-tidal sevoflurane concentration was changed. Predetermined end-tidal sevoflurane concentrations for each group were determined using the Dixon up-and-down method. After the target concentration of sevoflurane was maintained for 5 min, the child's trachea was intubated. Successful intubation was defined as excellent or good intubating conditions. The end-tidal concentration (SD) of sevoflurane for successful tracheal intubation in 50% of children (ED50) were 5.16 (0.22)% in control, 3.27 (0.18)%, 1.81 (0.20)% and 1.01 (0.11)%, in remi0.1, remi0.2, and remi0.3 groups, respectively. Using probit analysis, the 95% effective dose (ED95) of sevoflurane were 5.60% (95% CI 5.35,7.66), 3.77% (95% CI 3.45,7.74), 2.18% (95% CI 1.96,3.86), 1.19% (95% CI 1.06,1.82) in control, remi0.1, remi0.2, and remi0.3 groups, respectively. [source]


    Monitoring pollution by proton-transfer-reaction mass spectrometry during paediatric anaesthesia with positive pressure ventilation via the laryngeal mask airway or uncuffed tracheal tube

    ANAESTHESIA, Issue 7 2002
    J. Rieder
    Summary Twenty children aged 2,66 months were randomly allocated for airway management with either the laryngeal mask airway or uncuffed tracheal tube using intermittent positive pressure ventilation with a tidal volume of 8 ml.kg,1 and a respiratory rate adjusted to maintain end-expiratory carbon dioxide concentration at 5.3 kPa. Induction was with fentanyl/propofol and maintenance was with sevoflurane 2.5% in oxygen/air. The airway device was removed when the patients were awake and the patients were transferred to the postanaesthesia care unit 10 min later. Air was sampled from a point 1.5 m above the floor at a location remote from the ventilation outlet and analysed using a proton-transfer-reaction mass spectrometer capable of continuous trace gas analysis at the parts per billion volume (ppbv) level. The concentration of sevoflurane was recorded every minute during three consecutive phases: for 5 min before the introduction of sevoflurane (background); after introduction of sevoflurane until removal of the airway device (intra-operative); and every minute after removal until the concentration returned to background levels. Median (interquartile range [range]) intra-operative sevoflurane concentrations were 200,400 times higher than background values for the laryngeal mask airway 1 (1,2 [0,3]) ppbv vs. 404 (278,523 [83,983]) ppbv, respectively, and the tracheal tube 2 (1,3 [0,5]) ppbv vs. 396 (204,589 [107,1735]) ppbv (both p <,0.0001), and returned to background values within 5 min of removal. There were no differences in sevoflurane concentration between devices intra-operatively or after removal. The performance of the proton-transfer-reaction mass spectrometer was identical at the start and end of the 30-day study. We conclude that peri-operative sevoflurane concentration in a modern operating theatre is similar for the laryngeal mask airway and the uncuffed tracheal tube in paediatric patients receiving intermittent positive pressure ventilation. Intra-operative sevoflurane concentrations are five times lower than occupational safety limit requirements, and 1000 times lower 5 min after removal of the airway device with the patient awake. The proton-transfer-reaction mass spectrometer has potential for monitoring air quality in the operating theatre. [source]